Process for manufacturing finely-divided solid substances



PatentedAug. 24, 1 926.

- Qumran; STATES PATENT" OFFIGE.

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. ro'hrawing. Application filed au meso, 1921, serial 110. 97,021, a in Germany August 4 ,-'1o1 a.

I The applicability of many solid substances in the chemical industry is due to the fact that these substances are obtained in the.

form of a high grade. of dispersion.

Such finely divided substances are intended to be employed as contact substances for gaseous reactions or as adsorption means r 'clarifyin liquids and for precipitating dissolved, su ances, as mineral colours,

lopaqging means or as medicaments; They can produced in difi'erent manners, so that one and the same chemical individual may be obtained in a finely divided state in several ways, for instance by precipitating it from a-diluted solution or by decomposing solid compositions of a higher molecular the heat or finally by a pseudomorphous change of solid substances in solutions of the'reacting materials.

The grade of dispersion of one and the same substance manufactured according to different methods is, though generally characterized by the wordsffinely divided, not

always equal. 1 On the contrary, any method impresses special properties on the substance, owing to the co-operation of physical and chemical factors within the substance. On the other hand the varying purposes, for which finely divided substances are used, demand varying properties which in some cases can-be mparted to the substance only by the forming process itself and not by an additional treatment. In

.' such a case the evident looseness of the prodtric precipitating gas-ions,

.uct does not always determine its applicability, on the contrary in most cases the grade of dispersion. shows deeper lying differences, which are decisive.

Now, according to the resent invention a special stances may ressingthem in this medium, whereby it is necessary to conserve the original dimensions of the particles as far as possible.

. This result will be obtained by firstly pro" ducing the substances in question as smoke and then precipitating the latter by means of an electric treatment for instance by a point or corona discharge.

rocess is very well ,known. to'the art. The so id smoke particles-absorb when they pass a discharging field, and they are therefore quickly precipitated on. a collecting electrodei connected to the kind of dispersion of solid sub be obtained by firstly roduc-.

' generating furnace.

Such an e cothe interior structure of which is of a high grade of dispersion. The process can be used with respect. to all substances which are able to be vaporized and condensed again to the solid state. However, it can especially be carried out in such a manner that rimarily a substance difi'erent from the en -product will be produced in the form of vapour, whereupon the latter will be chemically converted into smoke correspondin to the end-product. So it is possible for lnstance to directly vaporize elementary substances or compositions and to recipitate these substances afterwards. oreover, it is possible to vaporize a metal and to convert this metal at the same time into an oxide, which then forms the smoke to be precipitated. Other substances, for instance the oxides of certain heavy metals, may be obtained in a high grade of dispersion by producing them together with other oxides in the form of smoke which recess can be carried out by subjecting their compositions or alloys together with aluminium, titanium, tin, silicium, vanadium, etc., to a blowing process. In such a case the oxides of these metals are used as carrying substances so that prod ucts of a' high chemical and catalytic activity are obtained. In this manner oxides,

for instance oxides of nickel and oxides of iron mixed with oxide of aluminium, oxide of silicium, oxide of titanium, etc., are reduced to pyrophoric products at extraordinary low temperatures.

In order to carry out the invention the evaporatic l is produced for instance by subjecting the substances to a blowing process with air or dioxide of carbon in a smoke Such oxides of metal are preferably produced by melting down the metals or their carbides in a luminous arc, whereas with respect to other more volatile, substances other heating means can be used. From the smoke generating furnace the'smoke preferably is led to a wide room,

in which it will be rendered homogeneous by means of a whirling motion and from this room it is directed to the electric precipitating room, which is constructed 1n a known manner. I I The process according to the present invention will clearly be shown by the following examples:

1. Metallic tin is'melted in an electric arc-furnace and afterwards a constant air dilute ammonia or hydrochloric acid. The result is a milky colloidal solution of a yellow tinge. Besides, this material is able to re.

I move, in a like manner as colloidal metastannic acid, phosphoric acid from a nitric acid solution. If the loose mass is heated, it is reduced to a small volume without loosing its high ad'e of dispersion, Consequently, this pro uct is especially capable to serve as opa uing means forglass and enamel.

- '2. W en metallic'bismuth is heated and 5 I a stream of airis blown upon it, it will be converted into a stron smoke of oxide, which can be precipitate as a loose brilliant lemon-coloured mass. This product shows all qualities, which render it applicable to china-painting inplace of the. bismuth ochre, used up to the present for this purose.

p 3. In order to produce oxides of metals on carriers for contact substances, electrically fused ferrotitanium or ferro-vanadium is subjected to a blowing process. By this means substances are produced of a varying ercentage of iron, showing a pyrophomc character after their reduction in .a stream of hydrogen, provided the have more than 30% of non. The finely vided state of the oxide of iron in these substances furthermore results from the fact, that already by the treatment with water a colloidal subdivision is obtained.

If alloys of nickel and aluminium will be treated in the same manner as above, mixtures of oxides are produced, which can directly be used as contact substances, though, their percentage of nickel is not higher I than 20%.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is z 1. A process for manufacturing finely di-' vided solid substances which consists in vaporizing-all the substances and producing them in form of finely divided systems in'a gaseous media and electrically precip-- itatin them from this media.

2. proces for manufacturing finely divided solid substances, which consists in directly vaporizing elementary substances and recovering them as solids of a high grade of dispersion by means of an electrical 3Q,

precipitation.

3. A process for manufacturing finely divided solid substances, which consists in directly vaporizing metal oxides and recovering them as solids of a high degree of dispersion by means of an electrical precipitation.

4. A process for manufacturing finely divided solid substances, which consists in f directly oxidizing and vaporizing elementary metallic substances, conyertin the vapour into smoke and recovering 't e solids from the smoke by electrical precipitation.

5. A process for manufacturing finely divided solid substances, which consists in va-' porizing a mixture of substances under oxidizing conditions, whereby oxides are formed and electrically precipitating this mixture in such a manner that a relatively indiiferent component is caused to form the carrier for an active component.

6. A process of making very fine metal oxid which comprises meltin a metal-containiug material, and directing a blast .of

oxidizing ga against the same while at a temperature at which such metal will oxidize and the oxide will volatilize, and thereafter subjecting the fume to electrical pre- 01 itation.

A process of making very fine metal oxid which com rises melting a metal-contaming materi containing metallic tin, and directing a blast of oxidizing gas against the same while at a temperature at which such metal will. oxidize and the oxide will volatilize, and thereafter subjecting the fume to electrical precipitation.

8. A process of makin very fine metal oxid which comprises me ting a metal-contaming material containing a metal having a relatively low melting and boiling point, and directing a blast of oxidizing gas against the same while at a temperature at which 9. The process for the production of finely subdivided solid substances of a high de cc of dispersion, which consists in first p ucing these substances in the form of finely dispersed systems in a gaseous medium, by f heating said substances considerably above the temperatures at which fumes are ordinarily formed (thereby producing substa'ntially only vapors without fumes in saiddiumby electrical precipitation.

10. The process for the production of finely subdivided solid substances of a high degree of dispersion, which consists in firstpioducing these substances in the form of ely dispersed systems in a aseous medium, by heating elementary su stances under oxidizing environment, to considerably above the temperature at which fumes are ordinarily formed, thereby producing substantially only vapors Without fumes 1n said gaseous medium, and then condensing said vapors from said medium into fumes, and precipitating said substances from said medium by electrical precipitation.

"11,- The process for the production of finely subdivided solid substances of a high degree of dispersion, which consists in first roducing these substances in the form of nely dispersed systems in a gaseous medium,

by heating metal containing compositions under oxidizing environment, to considerably above the temperature at which fumes I v are ordinarily formed thereby producing substantially only vapors without. fumes in said gaseous medium, and then condensing said vapors from said medium into fumes, and precipitating said substances from said medium by electrical precipitation.

12. The process 'for the production of finely subdivided solid substances of a high degree of dispersion, which consists in first producing these substances in the form of finely dis rsed systems in a gaseous medium, by eating 'e ementary substances considerably above the temperature at which fumes are ordinarily formed thereby roducing substantially only vapors wit out fumes in said gaseous medium, and then condensing said vapors from said medium into 1 fumes by means of a chemical reaction, and precipitating said substances from said .medium by electrical precipitation.

13. The process for the production of finely subdivided solid substances of a high degree of dispersion, which; consists in first producing these substances in the form of finely dis ersed systems in a gaseous medium,-by eating compositions considerably above the temperature at which fumes are ordinarily formed thereby producing substantially only vapors without fumes in said gaseous medium, and then condensing said vapors from said medium into fumes by means of a chemical reaction and tating said substances from said me 'um by electrical precipitation.

14. The process for the production of finely subdivided solid substances of a high degree of dispersion, which consists in first producing these substances in the form of finely dispersed systems in a gaseous merecipidium, by heating a mixture of substances considerably above the temperature at which fumes are ordinarily formed thereby producing substantially only vapors without fumes in said gaseous medium, and then condensing said vapors from said medium by electrical precipitation, so that indifferent components are the carriers for other components.

DR. VOLKMAR KOHIiSCHUTTER. 

